Today on Planet 100: The Top 5 Superhero Animals (Video)

From courageous dogs to beneficent goats, today's Planet 100 honors the top five animal heroes.Dog is Man's best friend. It's a classic saying; one any pet owner could find an example to illustrate. But these five animals prove that it's not only dogs doing what they can for human companions. Indeed, these heroes have all gone above and beyond to protect, defend, and save the life of a person.